The collection covers Pyman's career from 1937 until 1963 when he suffered a severe stroke which forced his retirement in 1964. The earliest papers date from Pyman's work with the Royal Tank Cadre in converting the 17/21 Lancers from a cavalry to an armoured regiment. There are also papers from Pyman's period as an instructor at the Staff College in Quetta, India, 1939-1941. Pyman was involved in the World War Two campaigns by the 8 Army in the Western Desert, in 1941 as General Staff Officer with 7 Armoured Div, 30 Corps and in 1942-1943 as Commander of the 3 Royal Tank Regiment, 10 Armoured Div, 30 Corps. The papers consist mostly of Pyman's assessments of lessons learned from the ongoing campaigns particularly with regard to tanks and armoured units. In 1944-1945 Pyman was Brigidier General Staff, 30 Corps, 2 Army in the Normandy landings and the invasion of Northern Europe, with particular responsibility for organisation and planning of the Rhine crossing and advance to the Baltic. This is reflected in the papers which largely consist of planning studies and reports for the operations involved, this section also contains maps used in the campaign. Pyman's next appointment was as Chief of General Staff, Allied Land Forces, South East Asia, 1945-1946 which is documented by a series of diaries which reflect the tasks faced by Pyman in this command including dealing with the build up of tension between newly liberated former colonies keen to assert their right for independence and the former colonial powers such as France and Netherlands. Pyman spent 1946-1949 as Chief of Staff, Middle East Land Forces and kept monthly diaries which form the bulk of this section of the collection. The diary entries and additional papers reflect the debate over policy in the Middle East in the British Government and Military command, they include detail on the British withdrawal from Greece, the problem of illegal Jewish immigrants and their internment in Cyprus, the end of the British mandate in Palestine and the the effect of this on relations between Britain with Egypt and the other Arab states and the subsequent Arab Israeli conflict. This section of the collection also contains correspondence between Pyman and Maj Gen Sir Miles Christopher Dempsey on personal matters and on the Middle East. There are also papers from Pyman's work at the Ministry of Supply as Director General of Fighting Vehicles, 1951-1953, Director of Weapons Development, War Office, 1955-1956 mostly brief diary entries and lecture texts. Pyman was also General Officer Commanding, British Army on the Rhine, 1953-1955 and General Officer Commanding, 1 British Corps, 1956-1958 and the papers relating to these commands consist mostly of lectures, reports and directives reflecting his interest in armoured divisions and training. There are some papers, mostly personal correspondence and press cuttings, from Pyman's final command as Commander-in-Chief Allied Forces Northern Europe in North Atlantic Treaty Organisation (NATO). The collection also contains correspondence relating to Pyman's role as Colonel Commandant of the Royal Tank Regiment and The Royal Armoured Corps and a series of letters covering the reorganisation of the Berks and Westminster Dragoons, of which he was Honorary Colonel. The rest of the collection consists of diaries, correspondence, speeches, writings including the draft copy and papers relating to his autobiography, some preparatory work on a history of the 2 Army and reference works. The collection also includes the Boer War diaries and other papers of Col James Redmond Patrick Gordon who commanded the 1 Cavalry Bde of the South African Field Force 1900-1901 which were given to Pyman by a friend.

Copies of papers relating to his career and the strategic significance of seapower, 1915-1962, including official and personal correspondence, 1915-1936, including letters from Adm Sir Arthur Cavenagh Leveson, Commander-in-Chief, China Station, 1923, R Adm Montagu William Warcop Peter Consett, 1923, V Adm Sir Lewis Clinton-Baker, 1926, Lt Gen John Greer Dill, 1929-1936, Adm Sir Herbert William Richmond, 1929, Maj Gen William Henry Bartholomew, 1929, R Adm Ragnar Musgrave Colvin, Chief of Staff, Home Fleet, 1931, Cdre Andrew Browne Cunningham, 1932; manuscript narrative diary, HMS HAREBELL, Fishery Protection, 1925-1926; typescript copies of lectures given at the Imperial Defence College, 1927-1935; manuscript notes on the history of the Peninsular Campaigns, Napoleonic Wars, 1807-1814 [1928]; published articles by Dickens, letters to the press and book reviews, mainly relating to the Royal Navy and the projection of seapower, 1929-1962; manuscript narrative war diary, 1940-1945, with manuscript notes on the Korean War, 1950; official and personal correspondence, 1940-1945, including letters from Rt Hon Maurice Paschal Alers Hankey, 1st Baron Hankey of The Chart, Chancellor of the Duchy of Lancaster, 1940, letter from Capt Wilfrid Rupert Patterson, Captain of HMS KING GEORGE V, on the sinking of the German battleship BISMARCK, 1941, letters from Adm Sir Andrew Browne Cunningham, 1st Bt, 1941-1944, letter from Augustus (Edwin) John, 1943, letter from R Adm John Anthony Vere Morse, 1943, letter from AF Sir John Cronyn Tovey, Commander-in-Chief, the Nore, 1945, also, typescript report by Dickens to the Admiralty on the German attack on the Netherlands, 22 May 1940 and copy of Adm Cunningham's official signal to the Admiralty on the surrender of the Italian Fleet, Malta, 10 Sep 1943; newspaper cuttings and correspondence relating to Bombing and strategy. The fallacy of total war (Sampson Low, Marston and Company, London, 1947), including letters of congratulation from Adm Cunningham, US Adm Richard L Conolly, Maj Gen John Frederick Charles Fuller, and Cdre Guy Willoughby, 1947; personal correspondence, 1947-1962, including letters from AF Andrew Browne Cunningham, 1st Viscount Cunningham of Hyndhope, 1947-1959, Adm Bruce Austin Fraser, 1st Baron Fraser of North Cape, 1948, Adm Sir (Eric James) Patrick Brind, Commander-in-Chief, Far East Station, 1949, Rt Hon Maurice Paschal Alers Hankey, 1st Baron Hankey of The Chart, 1949, AF Louis (Francis Albert Victor Nicholas) Mountbatten, 1st Earl Mountbatten of Burma, Commander-in-Chief, Mediterranean, 1954, AF Alfred Ernie Montacute Chatfield, 1st Baron Chatfield of Ditchling, 1959, R Adm George Pirie Thomson, 1959; manuscript notes and annotated typescript draft chapters for projected autobiography [1960].